Contrivance for transmitting sound to solid sound-conductors.



- 1,174,613. Patented Mar. 7,1916

' nansr RUHMER, or BERLIN, GERMANY.

' concrmvnncn 1 's -mAnsm1rrme sounn TO SOLID sounn-connuc'rons.

Specification of Letters Patent.

Patented Mar. 7,19ieQ Application filed February 20, 913, Serial No. 749,620; Renewed July 22,- 19 1 5. Serial no'.'41,42e.

, To all whom it may concern: Be itknown that I, ERNST RUHMER, subject of the Emperor of Germany, residing at Friederichstrasse 248, Berlin, S. 7., 4:8, 5 Germany, have invented a new and useful Improved Contriva'nce for Transmitting,

Soundto Solid Sound-Conductors, of which the following is a specification. y

v The present invention relates to a contrivance for transmitting sound and more especially speech vibrations, to solid sound conductors by means of a telephone or similar receiver, in which contrivance the va'riations of electric current corresponding .to

5 the speech vibrations or to the electro-mag; netic fluctuations genera-ted thereby, are translated'intomechanical vibrations.

The feature of the present invention resides in theemployment of a resilient aux-' 2 iliary element, which is itself set-in me- I chanical' vibration and is more or less fixed at one portion thereof but can freely vibrate elsewhere, for transmitting the electro-magnetic fluctuations or the vibrations of. a fixed vibratingelement, viz: the telephone dia.-

phragm, tothe solid sound conductor. The transmission of the fluctuations of the magnetic field of ,the telephone and the vibrations of the diaphragm thereof, to this aux'-" iliary conductor is eflected' atthe last men-i tioned freely vibratory portion, where thevibrations are of greatest amplitude,either' -magneticall 'v, mechanically or in some other manner,'while the propagation of the vibras5 tionsto the solid sound conductor occurs at or in theneighborhood of. the node of the auxiliary vibratory element. In this mani-"ner, to ajcertain extent,'a loose coupling is established between the' telephone receiver 40 and"thekpropagating element so that rela-,

tively little damping of, the vibrations takes place, whereas with a direct couplinglvery; V

. vibrating diaphragm', an elastic element, a

considerable damping would occur, render ing anypr'o'pag'ation of sound negligible. I

a The prese t contrivanfce is especially ap without necessarily traversing the external human organs of hearing, for the purpose of rendering a person, whose external or-= gans of hearing are defective but whose auditory nerves are still intact, receptive of ,56 sound waves.

In a constructional example of the inven- I claim: o I "i 1. In a 'contriva'nce for transmitting sound vibrations to'solid sound conductors,- V, I Z a telephone receiver, a diaphragm of said -tion illustrated iii-perspective on the accompanying drawing, the hearing apparatus consists of a clamp, comprising ranfinterrupted ring 1', which is contracted by apiece of rubber and is thereby pressed against the bones of the skull of the wearer thereof. Al

resilient spring bar 7 is secured to this ring, the upper portion of which is connected by a thread or wire (Z to the center of the dia phragm m of a telephone receiver t, carried by the clamp.

v On speaking into a microphone connected electrically to the-telephone, a'person wearing the contrivance hears the transmitted,-

sound waves,-without the latter having to ginning of this spe'cification.

telephone receiver, an elastic element se "cured at one portion thereof to the said solid sound conductor and a flexible-link connect portion of said elastic element. 3 A, I

a contriva'nce for transmitting sound to the bones-,of the human-head, a

clamp in close contact with the head, an elastic spring securedjat one portion thereof to said clamp, a telephone receiver carried on said clamp, a diaphragm ofsaid telephone receiver and alink connecting saiddiaphragm to a freely vibratory part of ,said' elastic'spring, g

for transmitting" sound 3. In ai -device vibrations to isolid t'soundl conductors, a

and said vibrating diaphragm, a"solid;sound conductor, -and a "close? coupling} Between said elastic element andsaidsolid"sou1i1 conductor. "3 .-'f.

4. In an apparatus for transmitting sound vibrations to solid conductors, a vibratory diaphragm, a solid sound, conductor, an elastic element which can vibrate with a loop at-o'ne end and anode at the other end, aconnection between said diaphragm and the loop end of said elastic element, and a connection between said solid sound con-\ 7 st" ingsaid diaphragm to a freely vibratory I ductor and the nodal an 5f saidelastic ele- In a. device forftransmitting' soun vibrations to solid sound conductors, a vibratory diaphragm, a solid sound conductor, an elastic element attached at one end to said solidssound conductor, and a flemble connection between said diaphragm "and the tached atone end to said diaphragm, and Ian elastic member secured to the other end of said flexible connecting member, whereby both of said members are normally held under tension, saidi elastic member being also connected with said solid; sound conductor. a

In testimony whereof I have signed my name to this specification in the presence of I two subscrlblng ,wltnesses.

ERNST RUHMER.

Witnesses KARL. HARLANDER, HENRY HASPER. 

